Blog

Home | Research | Publications | Outreach | About | Blog

October 12, 2020: Processing summer field data

Sunflowers at Laurenitis Farm in Sunderland, MA

Thank you to the farms who supported this research! The Bars, JM Pasiecnik, Dan’s Veggies, Laurenitis, Simple Gifts, Bardwell, Many Hands, Hampshire College, Red Fire, Natural Roots, Stone Soup, and Golonka.

This summer, I collected bees from multiple farms in Western Mass. The goal of this study is to determine if landscape floral diversity and amount of sunflower in the landscape affects the gut microbiome of these two species. Gut bacteria are important for bee health; they can help digest food and are certain bacteria are correlated with certain diseases. In order to better understand and protect our wild populations, I will be studying their gut microbes. The Adler Lab has recently discovered that when bees eat pollen from sunflowers, they have fewer gut parasites. I am curious to see if this link between their food and disease is driven by changes in their gut microbes.

I visited farms that differ in their amount of sunflowers planted to see if bees foraging in a landscape with lots of sunflowers (and lower overall diversity) have different gut microbes than bees in landscapes with a variety of flowering species, including some sunflowers, or a landscape with no sunflowers.

Rows of cut flowers at The Bars Farm in Deerfield, MA.

With help from an undergraduate assistant, Rose, I collected two species of bees that were foraging on sunflowers: Bombus impatiens and Halictus ligatus. I chose these two bee species because they differ in social behavior (bumble bees live in large colonies with a few hundred workers, while these sweat bees live in a solitary nest and do not have queens) but are similar in other ways – they are both generalist foragers (meaning they eat lots of different kinds of flowers) and live underground. Social behavior may impact the gut microbes so I hope to compare the patterns across sites between these two species.

From left to right: Two H. ligatus in ethanol, a Bombus queen foraging on a cosmos bloom, and a H. ligatus foraging on a sunflower.

Now that I’ve wrapped up my collections, I am processing the samples. My first step is to determine what types of pollen are on each bee, in order to see if the bee’s diet reflects the diversity of the landscape it was caught on. In other words – if there are lots of plants available to eat, do the bees actually have a more diverse diet? I hope that the types of pollen on their bodies will be an estimation of the food they are eating (although this is not perfect because some of the pollen they got on their bodies might not have been ingested, and they might have visited some other flowers just for nectar without getting any pollen on them). Later, I plan to sequence the DNA inside the gut of the bees to determine was bacterial species are present, and see how that correlates with their “diet” (pollen types/diversity on their bodies). For this, I have help from two undergraduates: Elisa, who is helping me make the slides, and Cristina, who is helping me quantify the different species of pollen found on each bee.

Some sunflower pollen that was removed from a bee and then placed under the microscope (400x magnification).

Thanks for checking in. I hope to have another update on the project in a few weeks! -Alison